I main Pantheon and the only real counters I've found are Cho'gath and Malphite. Malphite is amost always banned and Cho'Gath mainly jungles. He is one of the strongest champs in the game. His late game is bad if he builds pure damage. Almost got a penta today in solo que.

im surprised no one mentioned jayce? he's still rules top im my opinion that is :P i wonder if ap yi can do top also xD

I've played quite a deal games with pantheon and i've foung out the Cho'Gath is a strong counter against pantheon. Jax is another champ that can counter him but Nasus in my opinion is one of the best counters that i've experienced. He has superior sustain he can take all of Pantheons pokes and shrugh it of. He can push pantheon off lane if he wants to.